Heretofore, various curing agents were directly added to a rubber composition and mixed therewith. Problems were encountered with various specific types of curing agents with regard to dispersion, aggregates, and thus affected with physical properties thereof.
U.S. Pat. No. 4,113,799 to VanOrnum relates to an elastomer sealant composition having a high average molecular weight butyl rubber and a low average molecular weight butyl rubber in a ratio of between about 35/65 and 45/55 in admixture with a tackifier present in an amount of between about 55 and 70 weight percent of the composition.
U.S. Pat. No. 3,935,893 to Stang relates to a self-sealing vehicle tire and sealant composition having high molecular weight butyl rubber, a low molecular weight butyl rubber, a liquid polybutylene tackifier, a partially hydrogenated block copolymer of styrene and a conjugated diene, carbon black, and suitable curing agents for the butyl rubber.
U.S. Pat. No. 4,064,922 to Farber relates to a puncture sealant composition in tire having a major portion of a low molecular weight elastomer, a minor portion of high molecular weight elastomer and containing crosslinking agents in an amounts sufficient to give a partial cure.
U.S. Pat. No. 4,426,468 to VanOrnum et al relates to a sealant composition containing a cured butyl rubber present in the form of a copolymer having a molecular weight in excess of 100,000 and one or more tackifiers, wherein the tensile strength, elongation and crosslink density of the composition are adjusted to produce the necessary properties for tire sealants. Although para-quinone dioxime is blended in cyclohexanone to a dilution of about 40% solids by weight and added to a butyl rubber mixture and dispersed therein, the amount of solids is so great that a slurry exists. Many insoluble crystal sites exist for crystal growth and actually result in larger crystals upon mixing with the rubber cement.
U.S. Pat. No. 4,116,895 to Kageyama relates to a puncture sealant composition containing a crosslinking agent for rubber and a crosslinking activator. Various quinoids can be utilized as a crosslinking agent and are added directly to the rubber composition.
U.S. Pat. No. 2,765,018 to Connell and U.S. Pat. No. 4,256,158 to Chautard et al both relate to utilization of a quinoid curing agent which is directly added to a rubber composition.